What is the difference between Groups and Roles?

Groups in Mixmax allow you to share content, track performance and view metrics for your organization. You can read more about Groups here: Groups Overview

Roles allow you to set (and if you wish, enforce) settings for different departments or positions within your organization. E.g., you can determine what the default settings should be for Mixmax in general, Exclusions, Unsubscribing, and Tracking, or for key integrations like Salesforce. For tracking, this can help your organization comply with data privacy laws, as you can disable tracking for users in your organization by role. You can read more about that here: Disable tracking for your organization. 

You can create and assign roles from the Roles tab of Settings. You can also read more about Roles in this article.